Process for making carburetor float cups



Feb. 15,1927. F'HOLT V PRQCESS FOR MAKING CARBURETOR FLOAT CUPS FiledApril 29,- 1925 3 Sheets-Sheet 1 7 7112773 Half Marni/414 Feb. 159

1,617,906 F. HOLT PROCESS FOR MAKING CARBURETOR FLOAT CUPS Filed April29, 1925 3 Sheets-Sheet 2 A v munnnumnnng n 7 33 "fi -g a6 36- a fiifisssx Mmmmmw W4 Feb. 15,1927. Y 1,617,906

F.- HOLT PROCESS FOR MAKING CARBURETOR FLOAT CUPS Filed April 29 1925 5Sheets-Sheet 3 j f vmi eff/man??? 5 61771 Half Patented Feb. 15, 1927.

Uhll'lEi) STATES PATENT @EFEQE.

FRANK HOLT, OF CHICAGO, ILLTNGIS. ASSIGIIOR TO STRG'MBERG MOTOR DEVICESCOMPANY, F CHICAGO, ILLTNOIS A CORFORATION OF ILLINGI3. i

EROCESS FOR MAKING CARBUEETOR FLOAT CUPS.

Application filed April 29, 1925. Serial No. 26,626.

This invention relates to a process and dies for making a sheet metalcup for accommodating the fuel level controlling float in a carburetorand also the fuel supply controlling valve. and weight. the diameter ofthese-cups is usually made just large enough to accommodate thecylindrical float, and a: vertical ly extending outward deflection orbay is provided at one side of the cup for accommodating the fuel.outflow controlling valve which is usually adjustable at the top of thecup and engages at its lower end in a valve seat at the cup bottom.Heretofore, these float cups have usually been anintegral' part of thecarburetor body casting, and therefore required considerable finishingand structural work. It has been found that by using sheet metal in theconstruction of these float cups, the manufacture of a carburetor can begreatly simplified and the cost reduced and the object of this inventionis to provide an improved process for making the sheet metal cup andparticularly an improved step for forming the deflection for a valveaccommodating bay at the side of the cylindrical cup.

The construction of the cup is started from a flat piece of sheet metalwhich is drawn and subjected to die operation until there results astructure comprising a cylindrical body with a cover seating embryoflange at the top, and the invention is concerned particularly with adie process for.

reducing the diameter of this embryo cup and providing thereon the valveaccommodating lateral deflection or bay. Briefly defined, the processconsists in squeezing or compressing the body of the embryo cup betweenopposed die members having semicylindric pockets of a radius equal tothatot the desired radius of the finished cup, and the die members haveopposed recesses into which the surplus or deflected metal is forced toform the wall for the bay or channel which receives the fuel valve. Thepressure dies cooperate with a core die which extends into the cup anddefines or patterns the finished shape of the body.

My improved process and the dies are "fully illustrated on theaccompanying drawings, in which Fig. 1 is a plan view of the base orlower die part;

In order to reduce the space Fig. 2 is an under side view of the upperdie structure;

Fig. 3 is a sectional plane 3-3 of Fig. 1;

Fig. l is a sectional view on plane 4;t of Fig. 3;

Fig. 5 is a sectional view on plane 5 5 of Fig. 3;.

Fig. 6 is a plan view showing the embryo cup between thedie members.

Fig. 7 is a side elevational view of the finished cup; and

Fig. Sis a sectional view on plane 8-8 of Fig. 7.

The lower die structure, designated as a whole A, comprises the base 10having the opening 11 for receiving the supporting lug 12 of thesupporting block 13. At opposite sides of the supporting block, dieblocks 14: and 15 are slidable on the base 10, and are confined by theengagement of their side flanges 16 in recesses 17 and plates 18overhanging the recesses. As the body of cup to be formed iscylindrical, the die blocks have the semi-cylindrical die pockets 19 and20,

respectively, the supporting block 13 being also cylindrical and of thesame radius as the die ockets. The finished cup is shown in Fig. itcomprising the cylindrical body part 21, the lateral verticallyextending deflection or bay 22, and the top or cover sup-- portingflange 23. The radius of the supporting blocks and die blocks is equalto that of the body part of the finished cup.

Extending transversely on the base 10 outside of the die blocks M and15, are the walls 24 and 25 and from each of these die blocks rods 26extend, through openings in the respective walls between the outside ofwhich walls and the heads 27 on the rods compression springs 28 encirclethe rods, and these springs tend to pull the die blocks outwardly intoopen position to re eive the work which is to be formed. ,Pins 29secured in and extending from the die blocks, limit the outward movementof the die blocks by abutting against the. walls.

The upper outer corners of the die blocks 14 and 15 are beveled and haverectangular recesses 30 for the wearing or wedge surface plates 31 heldin place by screws 32.

The upper die structure comprises the base 33 from which extenddownwardly the rectangular die plungers 34 and 35, these plungers beingadjustably held in place by set screws 36 engaging their lugs 37 whichextend into the base 33. On their inner sides these die plungers are cutaway to leave the inclined or wedge surfaces 38 and the rectangular ends39, the slope of the wedge surfaces being the same as that of the plates31 on the die blocks 14 and The wedge surfaces 38 are vertically alignedwith the wedge plates, and when the die structures come together theplungers travel dow wardly between the walls 24 and 25 and the outersides of the die blocks, the openings 40 in the base 10 receiving theends 39 of the die plungers. After the wedge surfaces 38 come intoengagement with the wearing plates 31, further downward movement of theupper die structure will cause wedging engagement between the wedgesurfaces and powerful inward movement of the die blocks 14: and 15 toshape and form the cup structure between the die blocks. The diameter ofthe embryo cup. shown in Figs. 3 and 5 and in dotted lines in Fig. 6, isgreater than that of the finished cup shown in 7. The supporting block13 has the lateral vertical- 1y extending deflection or substantiallysemicircular lug 4C1 conforming in shape to the deflected part 22, whichis to be formed in the embryo cup. The adjacent corners of the dieblocks 14- and 15 are cut away to leave the die pockets or recesses 42and 43. which cooperate with the lug ll to shape the deflection 22. Theembryo cup is seated on the block 13 between the die blocks 14. and 15and with its flange overhanging the die block, as shown in Figs. 3. 5and 6. When the upper die structure is then forced downwardly into thelower die structure. the wedge surfaces referred to will powerfullyshift the die blocks 14' and 15 against and around the body of theembryo cup to squeeze and contract the body part and shift the metalinto the die recesses l2 13. The metal of the cup is guided by themandrel 4:4: secured to and extending from the base 33 of the upper diestructure. the diameter of this mandrel being that of the finished cup.

The mandrel has also the substantially semicircular projection or lug 45extending vertically thereon and in alignment with the lug 11 on thesupporting block 13. Thus,

3 when the die blocks 14 and 15 are forcibly brought together, the metalof the embryo cup will be drawn around the mandrel and around the lug 45to form the finished cup with the deflection 22 which provides space forthe fuel controlling valves. As shown in F 2, the lug 45 may form partof an insort 46 for the mandrel, so that after one insert is worn out,another can be readily applied.

An annular plate 17 surrounds the mandrel and is secured against theunder side of the base 33. Between this plate and a lower annular plate48 compression springs 49 are interposed which tend to hold the platesapart, and guide pins 50 which hold the plates in registration. When theupper die structure is brought down, the lower plate 18 will engageagainst the flange of the embryo cup and will force and hold the cup inposition between the die blocks while the cup is being formed. lVhen theupper die structure is then withdrawn. the plate 48 will be held pressedagainst the flange a sufflcient length of time to permit the mandrel toloosen itself from the formed cup and be readily withdrawn therefrom. Assoon as the upper die structure starts upwardly, the springs 28 willdraw the die blocks 14- and 15 away from the cup and the finished cupcan then be readily withdrawn.

By use of my improved process and dies in the formation of the floatcup, the cost of manufacture of carburetors can be materially reducedand the strength greatly inei'eased and the weight decreased.

1 claim the following 1. The process of forming a longitudinallyextending bay in the side of a cylindrical sheet metal cup whichconsists in constricting the cup in a single operation radially from topto bottom to smaller diameter and at the same time forcing the resultingfold laterally to form the bay.

2. lhe process of forming a sheet metal cylindrical cup of a certaindiameter into a cylindrical cup having a reduced diameter and alongitudinally extending outward deflection, which consists in radiallycontracting the cup from top to bottom in a single operation to thedesired diameter and, at the same time, forming the surplus materialinto the desired deflection.

In witness whereof, I hereunto subscribe my name this 22nd day of April,1925.

FRANK HOLT.

